Servetus was too vain and obstinate to take advice.
In the beginning of 1531, he secured a publisher for his book on the
"Errors of the Trinity," Conrad Koenig, who had shops at Basel and
Strassburg, and who sent the manuscript to Secerius, a printer at
Hagenau in Alsace. Servetus went to that place to read the proof. He
also visited Bucer and Capito at Strassburg, who received him with
courtesy and kindness and tried to convert him, but in vain.

In July, 1531, the book appeared under the name of
the author, and was furnished to the trade at Strassburg, Frankfort,
and Basel, but nobody knew where and by whom it was published.
Suspicion fell upon Basel.

This book is a very original and, for so young a
man, very remarkable treatise on the Trinity and Incarnation in
opposition to the traditional and oecumenical faith. The style is crude
and obscure, and not to be compared with Calvin’s, who
at the same age and in his earliest writings showed himself a master of
lucid, methodical, and convincing statement in elegant and forcible
Latin. Servetus was familiar with the Bible, the ante-Nicene Fathers
(Tertullian and Irenaeus), and scholastic theology, and teemed with
new, but ill-digested ideas which he threw out like firebrands. He
afterwards embodied his first work in his last, but in revised shape.
The following is a summary of the Seven Books on the
Trinity:—

In the first book he proceeds from the historical
Jesus of Nazareth, and proves, first, that this man is Jesus the
Christ; secondly, that he is the Son of God; and thirdly, that he is
God.10421042 "Primo, hic est
Jesus Christus. Secundo, hic est filius Dei. Tertio, hic est Deus."
(p. 1a.) He begins with the
humanity in opposition to those who begin with the Logos and, in his
opinion, lose the true Christ. In this respect he anticipates the
Socinian and modern humanitarian Christology, but not in a
rationalistic sense; for he asserts a special indwelling of God in
Christ (somewhat resembling Schleiermacher), and a deification of
Christ after his exaltation (like the Socinians).10431043 "Secundum carnem
homo est, et spiritu est Deus, quia quod natum est de spiritu, spiritus
est, et spiritus est deus. Et ita Esaiae 9. Puer natus est nobis,
vocabitur nomen eius deus fortis. Vide clare et dei nomen et
fortitudinem nato puero attributam, cui data est omnis potestas in
coelo et in terra. Et Thomas Iohannis 20. eum appellat, Deus meus,
Dominus meus. Et Rom. nono Christusdicitur in omnibus laudandus
et benedicendus. Multisque aliis locis eius divinitas ostenditur, quia
exaltatus est, ut acciperet divinitatem, et nomen super omne
nomen." 10a. He rejects the identity of the Logos with
the Son of God and the doctrine of the communication of attributes. He
distinguishes between the Hebrew names of God: Jehovah means
exclusively the one and eternal God; Elohim or El or Adonai are names
of God and also of angels, prophets, and kings (John
10:34–36).10441044 "Notes differentiam
inter הוהי proprium Dei nomen, et
לא
ינדא
ויהלא et alia similia Deo attributa. Et quod Thomas Iohannis 20. non
Iehovah, sed Elohim et Adonai de Christo dixerit, infra
probabo." 14a."Similiter
et וילא de
angelis et hominibus fortibus dicitur, Psal. 88 et Iob
41." 14b. He identifies Christ with
the Elohim instead of Jehovah. The prologue of John
speaks of things that were, not of things that are. Everywhere else the
Bible speaks of the man Christ. The Holy Spirit means, according to the
Hebrew ruach and the Greek pneuma, wind or breath, and denotes in the
Bible now God himself, now an angel, now the spirit of man, now a
divine impulse.

He then explains away the proof texts for the
doctrine of the Trinity, 1 John 5:7 (which he accepts as genuine, though
Erasmus omitted it from his first edition); John 10:30;
14:11; Rom. 11:36. The chief passages, the baptismal
formula (Matt. 28:19)
and the apostolic benediction (2 Cor. 13:14) where the Father, the Son, and the
Spirit are coordinated, he understands not of three persons, but of
three dispositions of God.

In the second book be treats of the Logos, the
person of Christ, and the Spirit of God, and chiefly explains the
prologue to the fourth Gospel. The Logos is not a metaphysical being,
but an oracle; the voice of God and the light of the world.10451045Λόγος non philosophicam illam rem, sed oraculum, vocem, sermonem,
eloquium Dei sonat. Usurpatur enim a verbo λέγωquod est dico."
47a. The Logos is a disposition or
dispensation in God, so understood by Tertullian and Irenaeus.10461046 "Per sacramentum
Verbi intelligit quandam in Deo dispositionem seu dispensationem, qua
placitum est ei arcanum voluntatis suae nobis revelare. Et hoc
Tertullianus οἰκονομίαν, et Irenaeus dispositionem scepissime
appellant." 48a. Before the incarnation the
Logos was God himself speaking; after the incarnation the Logos is
Jesus Christ, who makes God known to us.10471047 "Verbum in Deo
proferente, est ipsemet Deus loquens. Post prolationem est ipsa caro,
seu Verbum Dei, antequam sermo ille caro fieret, intelligebatur ipsum
Dei oraculum intra nubis caliginem nondum manifestatum, quia Deus erat
ille sermo. Et postquam Verbum homo factum est, per Verbum intelligimus
ipsum Christum, qui est Verbum Dei, et vox Dei, nam, quasi vox, est ex ore
Dei prolatus." 48a and b. He
refers for proof to Rev. 19:13: τὸ
ὄνομα
αὐτοῦ Ὁ
λόγος τοῦ
Θεοῦ. All that God before did through the Word, Christ
does in the flesh. To him God has given the kingdom and the power to
atone and to gather all things in him.

The third book is an exposition of the relation of
Christ to the divine Logos.

The fourth book discusses the divine dispositions
or manifestations. God appeared in the Son and in the Spirit. Two
divine manifestations are substituted for the orthodox tripersonality.
The position of the Father is not clear; he is now represented as the
divinity itself, now as a disposition and person. The orthodox
christology of two natures in one person is entirely rejected. God has
no nature (from nasci), and a person is not a compound of two natures
or things, but a unit.

The fifth book is a worthless speculative
exposition of the Hebrew names of God. The Lutheran doctrine of
justification is incidentally attacked as calculated to make man lazy
and indifferent to good works.

The sixth book shows that Christ is the only
fountain of all true knowledge of God, who is incomprehensible in
himself, but revealed himself in the person of his Son. He who sees the
Son sees the Father.

The seventh and last book is an answer to
objections, and contains a new attack on the doctrine of the Trinity,
which was introduced at the same time with the secular power of the
pope. Servetus probably believed in the fable of the donation of
Constantine.

It is not surprising that this book gave great
offence to Catholics and Protestants alike, and appeared to them
blasphemous. Servetus calls the Trinitarians tritheists and atheists.10481048 "Tritheitae ...
Athei, hoc est sine Deo." 21b. He frivolously asked such
questions as whether God had a spiritual wife or was without sex.10491049 "Debuissent dicere
quod habebat [Deus] uxorem quandam spiritualem, vel quod solus ipse
masculo-foemineus aut Hermaphroditus, simul erat pater et mater."
39b. This reminds one of the reasoning of the Mohammedans that
God has no wife, therefore he can have no son. He approves of the
objection of the Turks: "Nec mirum, si Turci nos asinarios vocant,
postquam nos Deum vocare asinum non erubescimus."
12a. He calls the three gods of
the Trinitarians a deception of the devil, yea (in his later writings),
a three-headed monster.10501050 The last expression I
could not find in the work De Trinitatis Erroribus, but it
occurs in his letters to Calvin, and in a letter to Poupin, where he
says: "Pro uno Deo habetis tricipitem cerberum."
Calvin’s Opera, VIII. 750. It was made the
chief ground of the charge of blasphemy at the trial in Geneva.
"Un Dieu party en trois ...
est uti diable àtrois testes comme le Cerberus que les
Poetesanciens ont appelléle chien d’enfer,
un monstre." Ibid. 728, Art.
IX. Tollin, in his article Der Verfasser de Trinitatis Erroribus ("Jahrbücher für protest. Theologie,"
1891, p. 414), derives these offensive phrases from the papal
controversialist Cochlaeus, who in his Lutherus septiceps, 1529,
says: "Quid ad haec Janus Bifrons? Quid Geryon Triceps? Quid
Cerberus trifaux? fabulae sunt poetarum et jocosa figmenta."
Cochlaeus compared these fables with the seven-capped Luther, who
surpassed them all in monstrosity.

Zwingli and Oecolampadius died a few months after
the publication of the book, but condemned its contents beforehand.
Luther’s and Bucer’s views on it have
already been noticed. Melanchthon felt the difficulties of the
trinitarian and christological problems and foresaw future
controversies. He gave his judgment in a letter to his learned friend
Camerarius (dated 5 Id. Febr. 1533): —

"You ask me what I think of Servetus? I see him
indeed sufficiently sharp and subtle in disputation, but I do not give
him credit for much depth. He is possessed, as it seems to me, of
confused imaginations, and his thoughts are not well matured on the
subjects he discusses. He manifestly talks foolishness when he speaks
of justification. peri; th'" triavdo" [on the subject of the Trinity]
you know, I have always feared that serious difficulties would one day
arise. Good God! to what tragedies will not these questions give
occasion in times to come: ei[ ejstin uJpovstasi" oJ logvo" [is the
Logos an hypostasis]? ei[ ejstin ujpovstasi" to; pneu'ma [is the Holy
Spirit an hypostasis]? For my own part I refer to those passages of
Scripture that bid us call on Christ, which is to ascribe divine honors
to him, and find them full of consolation."10511051 He adds in Greek that
it is not profitable to inquire curiously into the ideas and
differences of the divine persons. Opera, ed. Bretschneider, II.
630, and his letter to Brenz, July, 1533, II. 660. Also Tollin,
Ph. Melanchthon und M.
Servet, Berlin, 1876.

Cochlaeus directed the attention of Quintana, at
the Diet of Regensburg, in 1532, to the book of Servetus which was sold
there, and Quintana at once took measures to suppress it. The Emperor
prohibited it, and the book soon disappeared.

Servetus published in 1532 two dialogues on the
Trinity, and a treatise on Justification. He retracted, in the preface,
all he had said in his former work, not, however, as false, but as
childish.10521052 "Quae nuper contra
receptam de Trinitate sententiam, septem libris, scripsi, omnia nunc,
candide lector, retracto. Non quia falsa sint, sed quia imperfecta, et
tamquam a parvulo parvulis scripta .... Quod autem ita barbarus,
confusus et incorrectus, prior liber prodierit, imperitiae meae et
typographi incuriae adscribendus est." He rejected
the Lutheran doctrine of justification, and also both the Lutheran and
Zwinglian views of the sacrament. He concluded the book by invoking a
malediction on "all tyrants of the Church."10531053 "Perdat Dominus
omnes ecclesiae tyrannos. Amen."

1050 The last expression I
could not find in the work De Trinitatis Erroribus, but it
occurs in his letters to Calvin, and in a letter to Poupin, where he
says: "Pro uno Deo habetis tricipitem cerberum."
Calvin’s Opera, VIII. 750. It was made the
chief ground of the charge of blasphemy at the trial in Geneva.
"Un Dieu party en trois ...
est uti diable àtrois testes comme le Cerberus que les
Poetesanciens ont appelléle chien d’enfer,
un monstre." Ibid. 728, Art.
IX. Tollin, in his article Der Verfasser de Trinitatis Erroribus ("Jahrbücher für protest. Theologie,"
1891, p. 414), derives these offensive phrases from the papal
controversialist Cochlaeus, who in his Lutherus septiceps, 1529,
says: "Quid ad haec Janus Bifrons? Quid Geryon Triceps? Quid
Cerberus trifaux? fabulae sunt poetarum et jocosa figmenta."
Cochlaeus compared these fables with the seven-capped Luther, who
surpassed them all in monstrosity.

1051 He adds in Greek that
it is not profitable to inquire curiously into the ideas and
differences of the divine persons. Opera, ed. Bretschneider, II.
630, and his letter to Brenz, July, 1533, II. 660. Also Tollin,
Ph. Melanchthon und M.
Servet, Berlin, 1876.